IPAC2019 - Classification: MC8: Applications of Accelerators, Technology Transfer and Industrial Relations / U02 Materials Analysis and Modification

Paper	Title	Page
THXXPLS3	Science Frontiers of Megaelectronvolt Ultrafast Electron Probes
	X.J. Wang, R.K. Li, X. Shen, J. Yang SLAC, Menlo Park, California, USA
	Ultrafast electron probe is the new frontier for electron scattering instrumentations. The development in high-brightness electron beam made it feasible to explore megaelectronvolt electrons for Ultrafast Electron diffraction and Microsscopy (MeV-UED/UEM). Recent development in MeV-UED [2-3] has enabled broad scientific opportunities in ultrafast material science and chemical dynamics, such as the ripples of monolayer MoS2 and atomic movie of light-induced structural distortion in the perovskites solar cell were captured for the first time by the MeV-UED. Single-shot MeV-UED was successfully employed for the first observation of heterogeneous melting. In the gas phase UED, real space movie of a nuclear wavepacket passing through conical intersections was sucesffuly recorded *. To probe and controlling electron motion within a molecule and image bio-molecules in its nature environments, new generation electron scattering instruments with better time resolution, higher sensitivity and real space imaging are needed. SLAC’s strategy for next generation ultrafast electron instrument based on the superconductor RF gun will be discussed. X.J. Wang et al, Phys. Rev. E , 54, No.4, R3121 -3124 (1996). M. Z. Mo et al, Science 360 1451-1455 (2018). * J. Yang et al, Science, 361, 64-67. (2018).
	Slides THXXPLS3 [12.167 MB]
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THPMP026	Mobile Accelerator Based on Ironless Pulsed Betatron for Dynamic Objects Radiographing	3500
	V.A. Fomichev, A.A. Chinin, S.G. Kozlov, Yu.P. Kuropatkin, V.I. Nizhegorodtsev, I.N. Romanov, K.V. Savchenko, V.D. Selemir, O.A. Shamro, E.V. Urlin RFNC-VNIIEF, Sarov, Nizhniy Novgorod region, Russia
	The paper concerns a mobile accelerator based on the ironless pulsed betatron. The accelerator has a possibility to obtain up to three frames in a single pulse and is aimed to radiograph dynamic objects with a large optical thickness. The block diagram of the accelerator, the temporal diagram of its separate systems operation and oscillograms of the betatron output parameters are provided. The testing powering in a single frame mode was carried out in 2018. The capacitance of the storage of the betatron electromagnet pulsed powering system that defines the electron beam energy was equal to 1800 μF. The following test results have been obtained. The thickness of the lead test object examined with X-rays reached 140 mm at 4 m from the tantalum target of the betatron. The full width of the output gamma pulse at half maximum in a single frame mode was equal to 120 ns; the dimension of the radiation source was 6 mm x 3 mm; the dimension of the tantalum target was 6 mm x 6 mm. The application of these accelerators within the radiographic complex* enables the optimization of the hydrodynamic experiments geometry resulting in the increase of the test efficiency. * Pat. 2548585 C1 RU MPK G03B 42/02. D.I. Zenkov and others. «Mobile radiographic complex and radiation source of betatron type for radiographic complex» (in Russian), 2015.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP026
About •	paper received ※ 25 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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THPMP027	Concept of Radiographic Complex Based on Ironless Pulsed Betatrons for Small-Angle Tomography	3503
	O.A. Shamro, A.A. Chinin, V.A. Fomichev, Yu.P. Kuropatkin, V.I. Nizhegorodtsev, K.V. Savchenko, V.D. Selemir RFNC-VNIIEF, Sarov, Nizhniy Novgorod region, Russia
	The active research complexes intended for the radiography of dynamic objects with a high optical density are reviewed. The concept of a multi-beam radiographic complex for a small-angle tomography based on ironless pulsed betatrons is proposed. It is possible to use up to 18 compact facilities in a complex; they are located in three horizontal planes. The test object is placed in the explosion-proof chamber. Each facility consists of two typical units: an accelerator unit, and a unit of the electromagnet pulsed powering system. The output parameters of the facility are the maximum translucent capacity of 200 mm of the lead at 1 m from the betatron target, the resolution of less than 1 mm, the gamma-pulse full width at half maximum of 100 ns in a single frame mode, the gamma-pulse full width at half maximum of 150 ns in a three-frame mode. The complex will be able to obtain up to 54 frames in one hydrodynamic experiment at the operation of each facility in a three-frame mode. The complex is compact. Its diameter with a service area will be 20 m. Pat. 2515053 С1 RU МPK G03B 42/02. Yu.P. Kuropatkin, others. «Method of Radiograph. Image Form. of Fast Processes in Inhomogeneity and Radiograph. Complex for its Implementation», 2014.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP027
About •	paper received ※ 25 April 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
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THPMP053	Tuning Quadrupoles for Brighter and Sharper Ultra-fast Electron Diffraction Imaging	3571
	X. Yang, L. Doom, M.G. Fedurin, Y. Hidaka, J.J. Li, D. Padrazo Jr, T.V. Shaftan, V.V. Smaluk, G.M. Wang, L.-H. Yu, Y. Zhu BNL, Upton, Long Island, New York, USA W. Wan ShanghaiTech University, Shanghai, People’s Republic of China
	Funding: BNL LDRD We report our proof-of-principle design and experi-mental commissioning of broadly tunable and low-cost transverse focusing lens system for MeV-energy electron beams at the ultra-fast electron diffraction (UED) beam-line of the Accelerator Test Facility II of BNL. We exper-imentally demonstrate the independent control over the size and divergence of the electron beam at the sample via tunable quadrupoles. By applying online optimiza-tion, we achieve minimum beam sizes 75 µm from 1 to 13 pC, two orders of magnitude higher charge density than previously achieved using conventional solenoid tech-nique. Finally, we experimentally demonstrate Bragg-diffraction image (BDI) with significant improvement up to 3 times brighter and 2 times sharper BDI peaks via the optimized quadrupoles, improvement larger with higher charge. The result could be crucial for the future single-shot ultra-fast electron microscope development.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP053
About •	paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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THPRB056	Dose Measurement Experiments for Single and Composite Targets in 6 Mev Linear Accelerators	3937
	Z.H. Wang, J.Y. Liu, J. Shi, H. Zha TUB, Beijing, People’s Republic of China
	The target in electron linear accelerator plays an im-portant role in the production of photon. Targets of different materials and thicknesses have different X-ray yields. In this study, experiments were carried out to measure the dose rates of single targets and composite targets of different thicknesses for 6 MeV linear accel-erators utilizing ionization chamber. The electron ener-gy spectrum at the outlet of accelerating tube was de-tected with magnetic analyser. The experimental results show consistent rules with Monte Carlo simulations. Composite material target of 1.2 mm tungsten and 2 mm copper can deliver 1242 rad/min/100uA dose rate at 1 meter in front of the target. Dose rates of tungsten- rhenium alloy(74%W-26%rhenium) targets were exam-ined too.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB056
About •	paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

THXXPLS3

Science Frontiers of Megaelectronvolt Ultrafast Electron Probes

X.J. Wang, R.K. Li, X. Shen, J. Yang
SLAC, Menlo Park, California, USA

Ultrafast electron probe is the new frontier for electron scattering instrumentations. The development in high-brightness electron beam made it feasible to explore megaelectronvolt electrons for Ultrafast Electron diffraction and Microsscopy (MeV-UED/UEM)*. Recent development in MeV-UED [2-3] has enabled broad scientific opportunities in ultrafast material science and chemical dynamics, such as the ripples of monolayer MoS2 and atomic movie of light-induced structural distortion in the perovskites solar cell were captured for the first time by the MeV-UED. Single-shot MeV-UED was successfully employed for the first observation of heterogeneous melting**. In the gas phase UED, real space movie of a nuclear wavepacket passing through conical intersections was sucesffuly recorded ***. To probe and controlling electron motion within a molecule and image bio-molecules in its nature environments, new generation electron scattering instruments with better time resolution, higher sensitivity and real space imaging are needed. SLAC’s strategy for next generation ultrafast electron instrument based on the superconductor RF gun will be discussed.
* X.J. Wang et al, Phys. Rev. E , 54, No.4, R3121 -3124 (1996).
** M. Z. Mo et al, Science 360 1451-1455 (2018).
*** J. Yang et al, Science, 361, 64-67. (2018).

Slides THXXPLS3 [12.167 MB]

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMP026

Mobile Accelerator Based on Ironless Pulsed Betatron for Dynamic Objects Radiographing

3500

V.A. Fomichev, A.A. Chinin, S.G. Kozlov, Yu.P. Kuropatkin, V.I. Nizhegorodtsev, I.N. Romanov, K.V. Savchenko, V.D. Selemir, O.A. Shamro, E.V. Urlin
RFNC-VNIIEF, Sarov, Nizhniy Novgorod region, Russia

The paper concerns a mobile accelerator based on the ironless pulsed betatron. The accelerator has a possibility to obtain up to three frames in a single pulse and is aimed to radiograph dynamic objects with a large optical thickness. The block diagram of the accelerator, the temporal diagram of its separate systems operation and oscillograms of the betatron output parameters are provided. The testing powering in a single frame mode was carried out in 2018. The capacitance of the storage of the betatron electromagnet pulsed powering system that defines the electron beam energy was equal to 1800 μF. The following test results have been obtained. The thickness of the lead test object examined with X-rays reached 140 mm at 4 m from the tantalum target of the betatron. The full width of the output gamma pulse at half maximum in a single frame mode was equal to 120 ns; the dimension of the radiation source was 6 mm x 3 mm; the dimension of the tantalum target was 6 mm x 6 mm. The application of these accelerators within the radiographic complex* enables the optimization of the hydrodynamic experiments geometry resulting in the increase of the test efficiency.
* Pat. 2548585 C1 RU MPK G03B 42/02. D.I. Zenkov and others. «Mobile radiographic complex and radiation source of betatron type for radiographic complex» (in Russian), 2015.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP026

About •

paper received ※ 25 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMP027

Concept of Radiographic Complex Based on Ironless Pulsed Betatrons for Small-Angle Tomography

3503

O.A. Shamro, A.A. Chinin, V.A. Fomichev, Yu.P. Kuropatkin, V.I. Nizhegorodtsev, K.V. Savchenko, V.D. Selemir
RFNC-VNIIEF, Sarov, Nizhniy Novgorod region, Russia

The active research complexes intended for the radiography of dynamic objects with a high optical density are reviewed. The concept of a multi-beam radiographic complex for a small-angle tomography based on ironless pulsed betatrons is proposed*. It is possible to use up to 18 compact facilities in a complex; they are located in three horizontal planes. The test object is placed in the explosion-proof chamber. Each facility consists of two typical units: an accelerator unit, and a unit of the electromagnet pulsed powering system. The output parameters of the facility are the maximum translucent capacity of 200 mm of the lead at 1 m from the betatron target, the resolution of less than 1 mm, the gamma-pulse full width at half maximum of 100 ns in a single frame mode, the gamma-pulse full width at half maximum of 150 ns in a three-frame mode. The complex will be able to obtain up to 54 frames in one hydrodynamic experiment at the operation of each facility in a three-frame mode. The complex is compact. Its diameter with a service area will be 20 m.
* Pat. 2515053 С1 RU МPK G03B 42/02. Yu.P. Kuropatkin, others. «Method of Radiograph. Image Form. of Fast Processes in Inhomogeneity and Radiograph. Complex for its Implementation», 2014.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP027

About •

paper received ※ 25 April 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMP053

Tuning Quadrupoles for Brighter and Sharper Ultra-fast Electron Diffraction Imaging

3571

X. Yang, L. Doom, M.G. Fedurin, Y. Hidaka, J.J. Li, D. Padrazo Jr, T.V. Shaftan, V.V. Smaluk, G.M. Wang, L.-H. Yu, Y. Zhu
BNL, Upton, Long Island, New York, USA
W. Wan
ShanghaiTech University, Shanghai, People’s Republic of China

Funding: BNL LDRD
We report our proof-of-principle design and experi-mental commissioning of broadly tunable and low-cost transverse focusing lens system for MeV-energy electron beams at the ultra-fast electron diffraction (UED) beam-line of the Accelerator Test Facility II of BNL. We exper-imentally demonstrate the independent control over the size and divergence of the electron beam at the sample via tunable quadrupoles. By applying online optimiza-tion, we achieve minimum beam sizes 75 µm from 1 to 13 pC, two orders of magnitude higher charge density than previously achieved using conventional solenoid tech-nique. Finally, we experimentally demonstrate Bragg-diffraction image (BDI) with significant improvement up to 3 times brighter and 2 times sharper BDI peaks via the optimized quadrupoles, improvement larger with higher charge. The result could be crucial for the future single-shot ultra-fast electron microscope development.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP053

About •

paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB056

Dose Measurement Experiments for Single and Composite Targets in 6 Mev Linear Accelerators

3937

Z.H. Wang, J.Y. Liu, J. Shi, H. Zha
TUB, Beijing, People’s Republic of China

The target in electron linear accelerator plays an im-portant role in the production of photon. Targets of different materials and thicknesses have different X-ray yields. In this study, experiments were carried out to measure the dose rates of single targets and composite targets of different thicknesses for 6 MeV linear accel-erators utilizing ionization chamber. The electron ener-gy spectrum at the outlet of accelerating tube was de-tected with magnetic analyser. The experimental results show consistent rules with Monte Carlo simulations. Composite material target of 1.2 mm tungsten and 2 mm copper can deliver 1242 rad/min/100uA dose rate at 1 meter in front of the target. Dose rates of tungsten- rhenium alloy(74%W-26%rhenium) targets were exam-ined too.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB056

About •

paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)